Chain tension adjusting device



Jan 16, 1951 F. B. ENGEL y 2,538,675

CHAIN TENSION ADJUSTING DEVICE any.

Jan. 16, 1951 F. B. ENGEL 2,538,675

CHAIN TENSION ADJUSTING DEVICE Filed July 1e. `194s 2 sheets-sheet'z Eiga 3 A [g2 /4 @O @.O Il l /4- |||[l. n|||||| h 4 6 29 Patented Jan. 16, 17951 UNITED TAT vNr Manufacturing Company,

.Pennsylvania a corporation ,of

Application July 16, 1946, Serial No. 683,879

l1 Claims.

This invention relates to shovel loaders and more particularly to an improved adjusting device for elements of the drive of the bucket lifting mechanism of ra shovel loader.

An object of the present invention is to provide an improved adjusting device for elements of vthe drive of a shovel loader. Another object is to provide an improved eccentric adjusting device for a drive chain of ashovel loader whereby the sprocket centers may be relatively adjusted vto vary the tension of the chain. A further obj ect vai-242.16)

mechanism for the bucket of a shovel loader. The

' shovel loader may assume various forms but is is to provide an improved eccentric adjusting den vice for the drive Vchain for the lifting drums of the bucket lifting mechanism of a shovel loader. A still further `object is to provide an improved eccentric adjusting device for the bearing brackets of the chain drive rshaft of a shovel lloader. :Stillanother object is to provide an improved rotary eccentric mounting for the bearing brackets of a sprocket shaft whereby the sprocket centers of a drive chain may be relatively adjusted. A still further object is to provide an improved eccentric adjusting device for the Ybea-ring brackets .of the sprocket shaft and `embodying means for adjusting the bearing :bracket .into different predetermined positions. These and rother objects and advantages of the linvention will, however, hereinafter more fully appear in the course of the following description.

In the accompanying drawings there is shown -for purposes of illustration one form which the invention may Aassume in practice.

In Ythese drawings:

Fig. 1 is aside elevational View, with parts in longitudinal vertical section, of a shovel loader in which an illustrative form of the` invention is embodied.

Fig. 2 is a top plan View of the shovel loader Ashown in Fig. 1.

Fig. 3 is an enlarged cross-sectional view Vtaken `substantially on lines 3-3 of Fig. '1 and looking toward the vrear-end of rthe shovel loader.

Fig. 4 is an enlarged vertical sectional view taken substantially on lined-4 of Fig. 3, showing the chain drive of the bucket lifting mechanism.

Fig. 5 is a vertical sectional view taken substantially on lines 5-5 of Fig. 4, showing details of the eccentric adjusting device.

Fig. 6 is a `detail vertical sectional View taken on line 6 5 ofFig. 5.

Fig. 7 is a detail vertical sectional View taken Lshown embodied in the chain driveof lthe lifting herein of the same general character 'as that disclosed in the R. C. Osgood Patents No. 2,201,671, patented May 2l, 1940 and No. 2,268,857, patented January .6, 1942.

The shovel loader vgenerally' comprises -a portable base I having a base Aframe mounted ,on wheels 3, `3 adapted to travel along a trackway lll. Carried by the base frame is an upper frame 5 including vertical side ,plates 6, E `between which is mounted a vertically swingable shovel or bucket 'I. A conventional reversiblemotor A-8 (see Fig. l) .on the base `frame is `operrat/ively connected to the wheels 3 for propelling the loader backand forth along the trackway, and the traction of the wheels is utilized to ,effect .digging Qf ,the Shovel, when .the latter Ais inv vits lowered `digging position in Fig. l, into the material to'be loaded. Coupled to the rear end of the loader base is a mine c ar M havingits wheels guided on the trackway andthe shovel, when swung upwardly into its raised dumping position, discharges Aits contents -into the mine car. IIlhis structure is Lfully disclosed in the patents above referred to.

As vis also ,disclosed in the above mentioned patents, the shovel or bucket fl is suppOrlJQd by arms l,9 which carry rollers 9 guided lin substantially horizontal :guideways lll on lthe inner sides lof Ythe vertical side plates 6 of the upper frame A5. 'Ihus the rollers 9 `provide a rolling pivotal support for `the shovel and the shovel support- :ingarms are swingably supported to vturn on ,axes coincidental with lthe rollersupport axes vas the shovel is swung about its fulcrum point, andas the shovel is. swung upwardly from its lowered digging position, the rollers 9 .move rearwardly along the guideways l l) and the guideways serveto connue the shovel as it swings upwardly to .move in a predetermined .curved path. Secured `to `the shovel arms are semi-circular segments I l (see Fig. l) having cable guiding grooves on .their vcurved .peripheries for receiving pairs .of flexible ment of the shovelarms bodily longitudinally as they are swung and to provide, jin effect, a moving fulcrum .point for the shovel, and they serve to eiect movement of the shovel through :a wide arc as itmoves between its lowered digging position and its lraised dumping position. The arm segments, roller mounting and cable connections i yaeeacv 3 are fully described in the patents above referred to.

For raising and to control lowering of the shovel on its roller mounting, there are provided side chains hi, l suitably fastened to the shovel side arms 9 and wound on chain drums i5 (see Figs. 3 and 5) fixed to a transverse drive shaft i5 journaled in self-aligning anti-friction bearings il supported by brackets attached to the inner sides of the vertical side plates t in an improved manner to be later explained. A conventional reversible motor i9 is mounted on the upper rame and has its power shaft operatively connected to a chain drive sprocket 29 engaging an endiess drive chain 2 l, which, in turn, engages and drives a chain sprocket 22 fixed to the drum drive shaft i6 (Fig. 5) in adjacency to a chain drum. Carried by a cross plate 23 which braces the vertical side plates 6 above the drum drive shaft le are spring buffers 24 (Fig. 2) engageabie by the shovel supporting arms 9 to provide a cushioned stop for the shovel when the latter assumes its raised dumping position. When the rearward movement of the Shovel is abruptly stopped by the buffer springs, the shovel contents are discharged into the mine car M and the buffer springs also initiate forward return movement of the shovel from its raised dumping position, and when the center of gravity is passed, the shovel will drop down to its digging position under its own weight. y,

To speed up the return of the shovel, the shovel lifting motor i9 is reversed to rotate the chain drums i5 in unwinding direction so that the shovel may freely drop down into its digging position. This structure also is described in the above mentioned patents.

Now referring to the improved eccentric adjusting device associated with the drum drive shaft i6, it will be noted that the bearing brackets IS in which the shaft bearings Il are supported have circular projections 25 extending outwardly through circular openings 26 in the side plates s, and these circular projections have flattened surfaces 2'! exteriorly of the side plates for engagement by a suitable turning instrument such as a Wrench so that the bearing brackets i8 may be rotated into different positions. These circular projections 25 are eccentrically arranged with respect to the longitudinal axis of the drum drive shaft I as shown in Fig. 5 so that when the bearing brackets i8 are rotated, the longitudinal axis of the drum drive shaft may move in an arcuate path about the axes of rotation of the bearing brackets I8, as will later be explained. The vertical side plates E of the upper frame 5 are formed with a series of spaced, radially located openings 28, herein preferably four in number in each side plate, in which are received four bolts 29 for securing the brackets i8 to the side plates, and arranged in the side plates intermediate the openings 28 are similar openings 3i), likewise four in each plate. Thus there are eight holes, spaced apart, in each side plate. Formed in each of the bearing brackets l2 is a series of radially located openings 3 i, herein preferably twelve in number, and these openings are movable upon adjustment of the bearing brackets into registry with either the series of openings 23 or the series of openings 35i. The bearing brackets i8 may be rotated through i860, the twelve openings 3l in the bearing brackets are disposed 30 apart so that the bearing brackets may be adjusted into thirteen positions LSJ apart to move the longitudinal axis of the drum drive shaft IE through 180 from a lower position in a plane including the paraliel axes of the chain sprockets '2B and 22 to an upper position in the saine plane. The drive chain 2| is of the pivoted link type having its links pivotally connected together by parallel hinge pins in a conventional manner, and the axis of rotation of the chain sprocket 22 upon adjustment of the bearing brackets through is equal to half the distance between a pair of hinge pins so that when the total adjustment of the two sides of the chain has been made, the bearing brackets may be rotated to bring the longitudinal axis of the drum drive shaft i5 in its initial lower position back into the plane including the axes of the chain sprockets 28 and 22 so that a link may be detached from the chain to shorten the latter. Upon the removal of a link, any slackness in the shortened chain may be taken up by further adjustment of the bearing brackets. In pivoted link chains of certain types, it is necessary to remove two links and substitute an offset link in order to shorten the chain in the above manner. When the bolts 29 are removed, the bearing brackets may be turned to bring certain of the openings 3l into registry with the plate openings Sil, and the bolts 23 may be inserted in the plate openings 3G in an obvious manner. It will be evident that a greater or less number of openings may be provided in the bearing brackets and side plates, as desired. By the provision of self -aligning bearings il, it is possible to adjust the bearing brackets iii individually, the bearings permitting tilting of the drive shaft IS during such independent adjustment.

As a result of this invention, an improved adjusting device is provided for elements of the drive of the bucket lifting mechanism of a shovel loader, whereby the driving elements may be relatively adjusted as desired. By the provision of the eccentric adjusting device for the drive chain of the shovel lifting mechanism, the distance between the chain sprockets may be readily adjusted to vary the tension of the drive chain, By associating the eccentric adjusting device with the bearing brackets for the drum drive shaft of the shovel lifting mechanism, the structure is simplified and may be adapted to a conventional shovel loader with a minimum of change. The adjusting device is simple and rugged in design and may be easily adjusted into position simply by removing the attaching bolts, rotating the bearing brackets and reinserting the attaching bolts. These and other advantages of the invention will be clearly apparent to thos skilled in the art.

While there is in this application specifically described one forni which the invention may assume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is:

l. In an eccentric adjusting device for a transmission chain, the combination with a drive sprocket, a driven sprocket, an endless transmission chain engaging said sprockets, a shaft to which one of said sprockets is secured, a bearing bracket for said shaft and a support for said bracket, of an adjustable eccentric mounting for said bearing bracket including an eccentric portion on the latter engaged in a bore in said support, said shaft journaled in said bracket on an i axis offset from and parallel to the axis of said eccentric portion, said bracket being adjustable on its eccentric mounting t'o move said shaft in an arc struck from the eccentric'portion axis bodily to change the position of the axis of said shaft to vary the distance between the sprocket axes, thereby toadjust the chain tension.

`2. In an eccentric adjusting device for a transiiiiss'ion chain, the combination with a transmission shaft, a bearing bracket 'for said shaft in which the latter is journaled, 'a support for said bracket, a drive sprocket, a driven sprocket, one of said sprockets secured to said shaft, and an endless transmission chain engaging said sprockets, of an eccentric mounting for said bearing bracket on said support, said bracket being adjustable on its eccentric mounting to move said shaft in an arc to vary the distance between the sprocket axes, thereby to vary the chain tension, and means for securing said bracket to said 'i support in its different adjusted positions.

3. In an eccentric adjusting device for a transmission chain, the combination with a shaft, a bearing bracket in which said shaft is journaled, a support for said bracket, a drive sprocket, a driven sprocket, one of said sprockets being secured to said shaft and an endless transmission chain engaging said sprockets, of an eccentric mounting for said bearing bracket on said support, said bracket being adjustable on its eccentric mounting to move said shaft in an arc to vary the distance between the sprocket axes,

,thereby to vary the chain tension, and means for securing said bracket to said support in its diierent adjusted positions and including bolts receivable in registering openings in said bracket support and said bracket.

e. An eccentric adjusting device for a transmission chain comprising, in combination, a transmission shaft, a bearing bracket for said shaft, a bracket support, said bearing bracket having a circular projection arranged eccentrically with respect to the longitudinal axis of said shaft and rotatably mounted in a circular opening in said bracket support, a series of spaced openings in said bracket movable upon rotation of said bracket with respect to its support into registry with openings in said support, and bolts receivable in the registering openings for securing said bracket in adjusted position to said support, said bracket upon release of said bolts being rotatable on its eccentric mounting to move said shaft in an arc.

5. An eccentric adjusting device for a transmission chain comprising, in combination, a transmission shaft, a bearing bracket for said shaft, a bracket support, said bearing bracket having a circular projection arranged eccentrically with respect to the longitudinal axis of said shaft and rotatably mounted in a circular opening in said bracket support, a series of spaced openings in said bracket movable upon rotation of said bracket with respect to its support into registry with openings in said support, and bolts receivable in the registering openings for securing said bracket in adjusted position to said support, said bracket upon release of said bolts being rotatable on its eccentric mounting to move said shaft in an arc, and said circular projection extending outwardly from said bracket support and being formed for engagement with suitable turning means whereby said bracket may be rotated into its different adjusted positions.

6, An eccentric transmission adjusting means 6 comprising, in combination, a stationary frame, a transmission shaft, a bearing bracket for said shaft eccentrically mounted on said frame for rotary adjustment relative thereto, a driving element, a driven element operatively connected to said driving element, one of said elements being secured to said shaft, said bearing bracket being rotatable on its eccentric mounting relative to said frame to move said shaft bodily in a curved path to adjust the position of the element secured thereto with respect to said other element, and means for securing said bearing 'bracket in its adjusted position to said stationary frame.

'7. An eccentric transmission adjusting means comprising, in combination, a stationary frame, a transmission shaft, a bearing bracket for said shaft eccentrically mounted on said frame for rotary adjustment relative thereto, a driving element, a driven element 'operatively connected to said vdriving element, one of said elements being secured to said shaft, said bearing bracket being rotatable on its eccentric mounting relative to said frame to move said shaft bodily in a curved path to adjust the position of the element secured thereto with respect to said other element, and means for securing said bearing bracket in its adjusted position to said stationary Iframe, said securing means including openings in said bracket movable into registry with openings in said frame and securing bolts receivable in the registering openings.

8. An eccentric transmission adjusting means comprising, in combination, a stationary vertical frame, a transmission shaft,` a bearing bracket for said shaft eccentrically mounted on said frame at the inner side thereof for rotary adjustment relative thereto, a driving element, a driven element operatively connected to said driving element, one of said elements being secured to said shaft, said bearing bracket being rotatable on its eccentric mounting relative to said frame to move said shaft bodily in a curved path to adjust the position of the element secured thereto with respect to said other element, and means adjustable from the outer side of said frame for securing said bracket in its adjusted position with respect to said frame.

9. An eccentric transmission adjusting means comprising, in combination, a stationary vertical frame, a transmission shaft, a bearing bracket for said shaft eccentrically mounted at the inner side of said frame, a driving element, a driven element operatively connected to said driving element, one of said elements being secured to said shaft, an eccentric mounting for said bearing bracket on said frame including an outward eccentrically located cylindrical projection rotatable in an opening in said frame and eccentrically arranged with respect to the longitudinal axis of said shaft, said bracket being rotatable on said eccentric projection to move said shaft in a curved path to adjust the position of the element secured thereto with respect to said other element, and means for securing said bracket in its adjusted position to said frame, said bracket projection extending outwardly through its opening in said frame and formed exteriorly of said frame for engagement with suitable rotating means whereby said bracket may be rotated when said securing means is released.

10. A chain tension adjusting device comprising a stationary frame, a rotatable bearing bracket having a bore and a cylindrical projection arranged eccentrically with respect to said bore and rotatably supported on said frame, a bearing in assev said bore, a transmission shaft journaled in said bearing and arranged with its axis parallel to the axis of rotation of said eccentrically located projection, whereby said bracket provides an eccentric mounting for said shaft, a chain sprocket xed to said shaft, said bracket being rotatable on its eccentric mounting relative to said frame to move said shaft in an arc to change the location of the sprocket axis, and means for securing said bracket to said frame in its diierent positions of adjustment.

l1. A chain tension adjusting device comprising, in combination, spaced supports, a chain sprocket snaft arranged between said supports, eccentrically mounted bearing brackets carried by said supports respectively, self-aligning antifriction bearings carried by said brackets respectively, and in which the opposite ends of said sprocket-shaft are journaled, and means for effecting independent adjustment of said brackets to adjust said shaft bodily into different parallel positions with respect to said supports, said selfaligning bearings permitting tilting of said shaft with respect to its positions of parallelism without binding duringr such independent adjustment of said brackets.

FIESCO B. ENGEL.

REFERENCES CITED The following references are of record in the le of this patent:

UNITED STATES PATENTS Certificate of Correction Patent No. 2,538,675 January 16, 1951 FIESCO B. ENGEL It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 8, list of references cited, under UNITED STATES PATENTS add the following:

844,892 Pfander Feb. 19, 1907 2,281,875 Gleissner May 5, 1942 and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the ease in the Patent Office. Signed and sealed this 25th day of September, A. D. 1951.

THOMAS F. MURPHY,

Assistant Commissioner of Patents. 

